1. Field of the Invention
The present invention relates to a sheet conveyance device for conveying a sheet and an image forming apparatus provided with the sheet conveyance device.
2. Description of the Related Art
Recently, in the image forming apparatus such as a printer and a copying machine, a position of the conveyed sheet is detected with high accuracy, a position of an image recorded in the sheet is adjusted based on the detection result, and accuracy of image recording position is improved with respect to the sheet.
Particularly, in a sheet conveyance path, plural sensors are arranged in a sheet conveyance direction and a sheet width direction orthogonal to the sheet conveyance direction to continuously measure the position of the sheet, which allows inclination of the sheet and a sheet conveyance speed to be detected in addition to the position of a sheet end portion (for example, see Japanese Patent Application Laid-Open No. 6-135600). The image recording position is adjusted with respect to the sheet based on the detection information, and whereby the accuracy of image recording position is improved.
However, downsizing of the image forming apparatus is progressing recently. Particularly in the case of a tandem type image forming apparatus in which color image can be recorded, there is a restriction in space where each component unit is installed in the apparatus. Therefore, most part of the sheet conveyance path connecting the component units are formed in a curved shape. It is difficult that the sensors for detecting the sheet position are continuously disposed in the sheet conveyance direction in the curved conveyance path. Therefore, the accuracy of image recording position is hardly improved in the case of the image forming apparatus in which most part of the conveyance paths are formed in the curved shape.